DATACMNS-1755 - Use method references in favor of lambdas.

Simplify several lambda expressions in the codebase by using
method references.

Original pull request: #448.

src/main/java/org/springframework/data/auditing/AuditingHandler.java

@@ -195,8 +195,8 @@ public class AuditingHandler implements InitializingBean {
 			Assert.notNull(auditor,
 					() -> String.format("Auditor must not be null! Returned by: %s!", AopUtils.getTargetClass(it)));
 
-			auditor.filter(__ -> isNew).ifPresent(foo -> wrapper.setCreatedBy(foo));
-			auditor.filter(__ -> !isNew || modifyOnCreation).ifPresent(foo -> wrapper.setLastModifiedBy(foo));
+			auditor.filter(__ -> isNew).ifPresent(wrapper::setCreatedBy);
+			auditor.filter(__ -> !isNew || modifyOnCreation).ifPresent(wrapper::setLastModifiedBy);
 
 			return auditor;
 		});
@@ -216,8 +216,8 @@ public class AuditingHandler implements InitializingBean {
 
 		Assert.notNull(now, () -> String.format("Now must not be null! Returned by: %s!", dateTimeProvider.getClass()));
 
-		now.filter(__ -> isNew).ifPresent(it -> wrapper.setCreatedDate(it));
-		now.filter(__ -> !isNew || modifyOnCreation).ifPresent(it -> wrapper.setLastModifiedDate(it));
+		now.filter(__ -> isNew).ifPresent(wrapper::setCreatedDate);
+		now.filter(__ -> !isNew || modifyOnCreation).ifPresent(wrapper::setLastModifiedDate);
 
 		return now;
 	}

src/main/java/org/springframework/data/mapping/context/PersistentEntities.java

@@ -198,9 +198,9 @@ public class PersistentEntities implements Streamable<PersistentEntity<?, ? exte
 
 		Collection<PersistentEntity<?, ?>> entities = contexts.stream() //
 				.flatMap(it -> it.getPersistentEntities().stream()) //
-				.map(it -> it.getIdProperty()) //
+				.map(PersistentEntity::getIdProperty) //
 				.filter(it -> it != null && type.equals(it.getTypeInformation().getActualType())) //
-				.map(it -> it.getOwner()) //
+				.map(PersistentProperty::getOwner) //
 				.collect(Collectors.toList());
 
 		if (entities.size() > 1) {

src/main/java/org/springframework/data/mapping/context/PersistentPropertyPathFactory.java

@@ -47,7 +47,7 @@ import org.springframework.util.StringUtils;
  */
 class PersistentPropertyPathFactory<E extends PersistentEntity<?, P>, P extends PersistentProperty<P>> {
 
-	private static final Predicate<PersistentProperty<? extends PersistentProperty<?>>> IS_ENTITY = it -> it.isEntity();
+	private static final Predicate<PersistentProperty<? extends PersistentProperty<?>>> IS_ENTITY = PersistentProperty::isEntity;
 
 	private final Map<TypeAndPath, PersistentPropertyPath<P>> propertyPaths = new ConcurrentReferenceHashMap<>();
 	private final MappingContext<E, P> context;

src/main/java/org/springframework/data/mapping/model/AnnotationBasedPersistentProperty.java

@@ -310,7 +310,7 @@ public abstract class AnnotationBasedPersistentProperty<P extends PersistentProp
 		}
 
 		String builder = annotationCache.values().stream() //
-				.flatMap(it -> Optionals.toStream(it)) //
+				.flatMap(Optionals::toStream) //
 				.map(Object::toString) //
 				.collect(Collectors.joining(" "));
 

src/main/java/org/springframework/data/mapping/model/MappingInstantiationException.java

@@ -92,7 +92,7 @@ public class MappingInstantiationException extends RuntimeException {
 			}
 
 			return String.format(TEXT_TEMPLATE, it.getType().getName(),
-					constructor.map(c -> toString(c)).orElse("NO_CONSTRUCTOR"), //
+					constructor.map(MappingInstantiationException::toString).orElse("NO_CONSTRUCTOR"), //
 					String.join(",", toStringArgs));
 
 		}).orElse(defaultMessage);

src/main/java/org/springframework/data/repository/core/support/DefaultCrudMethods.java

@@ -176,8 +176,8 @@ public class DefaultCrudMethods implements CrudMethods {
 	private static Optional<Method> getMostSpecificMethod(Method method, Class<?> type) {
 
 		return Optionals.toStream(Optional.ofNullable(ClassUtils.getMostSpecificMethod(method, type)))//
-				.map(it -> BridgeMethodResolver.findBridgedMethod(it))//
-				.peek(it -> ReflectionUtils.makeAccessible(it))//
+				.map(BridgeMethodResolver::findBridgedMethod)//
+				.peek(ReflectionUtils::makeAccessible)//
 				.findFirst();
 	}
 

src/main/java/org/springframework/data/repository/query/SpelEvaluator.java

@@ -16,6 +16,7 @@
 package org.springframework.data.repository.query;
 
 import java.util.Map;
+import java.util.Map.Entry;
 import java.util.stream.Collectors;
 
 import org.springframework.data.repository.query.SpelQueryContext.SpelExtractor;
@@ -62,7 +63,7 @@ public class SpelEvaluator {
 		EvaluationContext evaluationContext = evaluationContextProvider.getEvaluationContext(parameters, values);
 
 		return extractor.getParameters().collect(Collectors.toMap(//
-				it -> it.getKey(), //
+				Entry::getKey, //
 				it -> getSpElValue(evaluationContext, it.getValue()) //
 		));
 	}

src/main/java/org/springframework/data/spel/EvaluationContextExtensionInformation.java

@@ -250,7 +250,7 @@ class EvaluationContextExtensionInformation {
 		 * @return the methods
 		 */
 		public MultiValueMap<String, Function> getFunctions(Optional<Object> target) {
-			return target.map(this::getFunctions).orElseGet(() -> new LinkedMultiValueMap<>());
+			return target.map(this::getFunctions).orElseGet(LinkedMultiValueMap::new);
 		}
 
 		private MultiValueMap<String, Function> getFunctions(Object target) {

src/main/java/org/springframework/data/web/PagedResourcesAssembler.java

@@ -94,7 +94,7 @@ public class PagedResourcesAssembler<T> implements RepresentationModelAssembler<
 	@Override
 	@SuppressWarnings("null")
 	public PagedModel<EntityModel<T>> toModel(Page<T> entity) {
-		return toModel(entity, it -> EntityModel.of(it));
+		return toModel(entity, EntityModel::of);
 	}
 
 	/**
@@ -107,7 +107,7 @@ public class PagedResourcesAssembler<T> implements RepresentationModelAssembler<
 	 * @return
 	 */
 	public PagedModel<EntityModel<T>> toModel(Page<T> page, Link selfLink) {
-		return toModel(page, it -> EntityModel.of(it), selfLink);
+		return toModel(page, EntityModel::of, selfLink);
 	}
 
 	/**
@@ -230,7 +230,7 @@ public class PagedResourcesAssembler<T> implements RepresentationModelAssembler<
 			resources.add(createLink(base, page.previousPageable(), IanaLinkRelations.PREV));
 		}
 
-		Link selfLink = link.map(it -> it.withSelfRel())//
+		Link selfLink = link.map(Link::withSelfRel)//
 				.orElseGet(() -> createLink(base, page.getPageable(), IanaLinkRelations.SELF));
 
 		resources.add(selfLink);

src/main/java/org/springframework/data/web/config/SpringDataWebConfiguration.java

@@ -169,7 +169,7 @@ public class SpringDataWebConfiguration implements WebMvcConfigurer, BeanClassLo
 		if (ClassUtils.isPresent("org.xmlbeam.XBProjector", context.getClassLoader())) {
 
 			converters.add(0, context.getBeanProvider(XmlBeamHttpMessageConverter.class) //
-					.getIfAvailable(() -> new XmlBeamHttpMessageConverter()));
+					.getIfAvailable(XmlBeamHttpMessageConverter::new));
 		}
 	}